RU2554166C1 - Charge-translator in conditionally non-destructive multi-layer shell - Google Patents

Abstract

FIELD: blasting operations.

SUBSTANCE: charge-translator in conditionally non-destructive multi-layer shell comprises a detonating elongated charge of circular cross-section of the crystalline high explosive in a metal shell with metal caps put on the ends and compressed and/or glued. The charge shell is made multilayer, consisting of one and/or two and/or more non-metallic layers of materials with different acoustic impedance. The layers are placed densely without air gaps on the detonating elongated charge. Each subsequent layer of the shell in motion of the shock wave from the charge axis to the periphery is more compressible than the previous one. The thickness of these layers is determined based on the condition of maintenance of the continuity of the metal shell of the detonating elongated charge p_out≤p_1cr, where p_out is the pressure on the outer surface of the outer shell of the charge-translator; p_1cr is critical pressure of destruction of the shell of the detonating elongated charge. The optimum thickness of the shell is 0.8÷1.2 mm, and the diameter of the explosive is not less than the critical diameter of detonation.

EFFECT: reduction of the level of impact loads directly at the moment and after actuation of the device.

3 cl, 3 dwg

Description

The invention relates to devices and systems for on-board pyroautomatics of aircraft (LA) and can be used to translate (dilute, multiply) a detonation pulse to a distance from a detonation initiation source (means, initiation system) to pyrotechnic or pyromechanical actuators, separation, throwing and etc.)

The invention can also be used in perforated explosive equipment for oil, gas and other wells.

It is well known that general-purpose detonating cords (LH) of various grades of small, medium, and normal power are designed to transmit a detonation pulse to a distance both from the means of initiation to the explosive charge (explosive) and between individual explosive charges in order to simultaneously undermine them. (Engineering ammunition. Guidance on material and application. Book 1. - M .: Military Publishing House, 1976; Metal cutting by explosion / A.V. Attetkov, AM Gnuskin, V.A. Pyryev, G.G. Sagiddulin. - M .: SIP RIA, 2000). Domestic DWs used to transmit detonation have a core made of PETN or bulk hexogen coated with a multilayer braid made of linen, cotton, dacron and kapron threads and yarn with a water-insulating mastic, and some have a plastic sheath. The detonation velocity LH - 5000 ÷ 7000 m / s; the mass of explosives per unit length of the cord varies from 5 ÷ 6.5 g / m (low-power DS) to 11.5 ÷ 14.5 g / m (medium power) and even up to 47 ÷ 53 g / m (high power).

The disadvantages of almost all LH, limiting or even excluding the possibility of their use in pyroautomatic systems of aircraft, is the excessive power of the explosion during detonation with the formation of a large number of both gaseous detonation products and the condensed phase (k-phase) in the form of soot, soot, the creation of significant shock loads on nearby nodes, units, office and scientific equipment and the aircraft itself. In addition, accidents have a large spread in the values of the detonation velocity and relatively low reliability of visual monitoring of the health of the mounted explosive network, the impossibility of its instrumental verification. The reason is the low density of the core from the explosive (almost bulk density) and the possibility of the formation of voids in the core during the manufacture of accidents. Finally, the excessive design flexibility of the aircraft complicates their layout and mounting on board the aircraft.

Flexible linear detonating elements (cords, ribbons) are known as on a ballistic basis, for example, the composition “elastit” (Zhegrov E.F., Milekhin Yu.M., Berkovskaya E.V. Chemistry and technology of ballistic powder, solid rocket and special fuel oils T. 1 Chemistry: Monograph - M .: RIC MGUP named after I. Fedorov, 2011.), and based on highly dispersed explosives (PETN, RDX or HMX), thermoplastic elastomers and rubbers, for example, explosives EVV-22, EVV -1NF, EVV-2NF, "Elas-1", "Elas-2" (Kotomin A.A. Elastic explosive materials // Russian Chemical Journal , 1997, T. 41, No. 4; Efanov VV, Moisheev AA Fundamentals of the design of detonation devices and separation systems for spacecraft: a Training Manual, - M .: Publishing House MAI-PRINT, 2010), The lack of flexible of linear detonating elements based on elastic explosives, as well as detonating cords, is the formation of a large number of explosion products with an increased content of the k-phase when they are triggered, the difficulty of installing them at the facility due to their high flexibility, and also insufficiently high performance characteristics, such as thermal resistance (especially to low, negative temperatures), radiation resistance; their warranty storage period does not exceed five years.

Known shock wave tubes - waveguides that are part of the so-called initiation systems with low-energy pulse conductors - domestic SINV, UNSI, EDELIN systems, as well as NONEL systems from Dino-Nobel, EXEL from IC-Ai, PRIME firm from Inside-Bickford , DYNASHOK company Dynamite Nobel (Graevsky M.M. Handbook for the electric explosion of explosive charges. Ed. 2nd, revised and add. - M .: Rendezvous-AM, 2000,). A plastic multilayer (in the NONEL system - three-layer) waveguide tube with an external diameter of 3.5 mm (for domestic SINV) has an explosive sputtering on the inner surface with a weight of about 20 mg / m. The transmission speed of the initiating pulse is about 2000 m / s. When detonation passes through a thin arch of explosives, the shell undergoes minor stresses mainly in the elastic region of deformation. As a result, after operation, the waveguide tube retains its integrity; gaseous detonation products turn out to be canalized inside the waveguide tube. The disadvantages of such devices are low reliability due to possible violations of the continuity of explosive spraying along the entire length of the waveguide tube, the use of a special explosive device that gives a high-energy spark to activate the waveguide tube, relatively low structural rigidity, low initiating pulse, and low radiation and thermal resistance of polymer materials of waveguide tubes. The listed characteristics are important when using these devices on board such aircraft as spacecraft, rocket blocks.

The probability of breaking the continuity of explosives along the charge length is significantly reduced (compared with the previous analogue) in the construction of the well-known linear charge-translator of detonation commands with low side brisant effect (Swiss patent 520085 IPC C06C 5/04, publ. 04/28/1972). The explosive charge (RDX, TENA) is placed in the annular channel between the outer and inner thermoplastic shells. The susceptibility of this device to detonation is much higher than the previous described designs (detonated from conventional standard means of initiation with amplifying charges), and their initiating impulse is higher. However, the remaining disadvantages listed for previous devices are inherent in them.

A significant increase in the initiating pulse and ensuring sufficient structural rigidity was achieved in the well-known linear charge-translator of detonation ring-type commands (patent RU 2134254 C1, IPC C06C 5/04, published on 08/10/1999). The charge-translator consists of the outer and inner coaxial shells (usually metal), the explosive charge placed between them (in the diametric section has the shape of a ring), a through channel located along the axis of the charge, filled with a low-compressible medium (liquid), and sealing caps. Due to the implementation of pulsating detonation, the propagation velocity of the process in such a charge reaches 12,000 m / s (for RDX) and more, and the initiating pulse increases by more than 30% compared to the previous device. The disadvantages of such translator charges are the low manufacturability of the manufacturing process, especially charges of a sufficiently long extent, the difficulty in ensuring the constancy of the thickness of the explosive ring over the entire cross section of the charge, the exclusion of cracks, breaks in the explosive when the charge-translator is laid out over a complex surface, and the difficulty of initiating detonation in explosive ring charge through the sealing cap.

Known and widely used in practice in separation systems for aircraft and in perforating explosive equipment designed to open, increase recovery and separation of layers, to eliminate accidents in oil and gas wells, detonating elongated charges (DUZs) of circular cross section (without cumulative excavation). Structurally, they are a charge of a high-sheen crystalline individual explosive (HMX, RDX, GNDS, etc.) of high density, most often enclosed in an aluminum or copper shell (in the technical literature it is called “curb pipe” - TSN) worn on the ends and crimped or metal caps put on glue (Auxiliary systems of rocket and space technology / Ed. by I.V. Tishunin, - M.: Mir Publishing House, 1970; Metal cutting by explosion / A.V. Attetkov, AM Gnuskin, V .A. Pyryev, G.G. Sagi Ullin. - M.: SIP RIA, 2000; TU 84-776-78. Long detonating charges. - entered 01.01.79, 1978; TU 84-07513406-033-94. DUZ charges. Technical conditions - introduced 15.09. 95, 1995.) Remote sensing devices reliably (reliability index 0.9 ³ and higher at α = 0.95) detonate from any standard means of initiation or from a segment of another remote sensing device and transmit the detonation pulse at any distance and in any medium with a constant speed regardless from the parameters of this environment.

The material of the DUZ shell extremely strongly affects its explosive and technical characteristics, primarily such as the pressure on the outer surface of the shell and the speed of expansion of shell fragments. Ceteris paribus (the same type of explosive, the same diameter of the equipment), remote sensing systems in aluminum shells are more preferable for solving problems of broadcasting detonation commands in comparison with, for example, charges in copper shells. This is explained quite simply. DLDs in aluminum shells have a lower density ρ _in explosives (equipment) than similar charges in copper shells. So, elongated charges with RDX equipment, made by drawing by technology of the Military Academy. F.E. Dzerzhinsky (now the Military Academy of the Strategic Missile Forces named after Peter the Great), have a density ρ _in = 1.54 ± 0.2 g / cm ³ and ρ _in = 1.72 ± 0.2 g / cm ³ in aluminum and copper shells respectively. As is known (Explosion Physics / Ed. By L.P. Orlenko. - Ed. 3rd, revised. - V. 2 vol. - M .: FIZMATLIT, 2002), the density of an explosive has an effect on such parameters, as the detonation velocity D and the polytropic index n (often referred to in the literature as the isentropic index or the adiabatic expansion coefficient of detonation products). So, for calculating the detonation velocity and the polytropic index of RDX, the following formulas are valid:

Rostika

D = 7995 + 3326 (ρ _at -1.6)

or cook

D = 6080 + 3250 (ρ _in -1) and

n = 1,85 + 1,15ρ _in / ρ _u

where ρ _mc is the density of the explosive single crystal; [ρ _in ] = [ρ _mk ] = g / cm ³ .

Given that the dependence n = n (ρ _in ) is less "strong" than D = D (ρ _in ), the detonation pressure p _N (also called the Hugoniot pressure), determined by the obvious dependence

for charges in aluminum shells, it will be 18 ÷ 20% less than for similar charges in copper shells. In this case, the pressure gain p _x on the “BB - shell" contact surface, which is determined for the case of sliding detonation by calculation by solving a system of two obvious equations

where u _x is the mass velocity of the particles in the front of the shock wave, ρ ₀ is the density of the material of the medium (DZS shell); A and m are the parameters of shock compressibility of the shell in the form of Theta, for charges in aluminum shells it will be more than 30%. The pressure in the shock wave on the outer surface of the aluminum sheath will be less by about the same amount compared to the copper sheath (with the same thickness). Accordingly, the expansion speeds of the fragments of the aluminum shell after its destruction will be significantly lower as compared to the fragments of the copper shell. For this reason, DLDs in an aluminum shell are preferable to use as translators of detonation commands than charges in copper shells, and DLDs in accordance with TU 84-776-78 and TU 84-07513406-033.94, made in aluminum shells, are taken as known closest to the claimed device.

With high reliability of the action of the prototype device, serious flaws are inherent that limit its use as a charge-translator of detonation commands in on-board pyroautomatic systems. Firstly, it has the same drawback as LH, namely, the formation, when triggered, of a large number of detonation products containing, in addition to gaseous substances, the k-phase and strong side effects, shock loads on nearby nodes, product assemblies, service and scientific equipment. In addition, when the DLD is triggered, as mentioned above, the destruction of the metal shell with the formation of a large number of high-speed fragments occurs; to intercept and capture them, it is necessary to install massive screens or traps on board in the layout zone of the remote sensing systems, which greatly degrades the mass-dimensional characteristics of both the broadcast system of detonation teams and the aircraft as a whole. This makes it inappropriate to use traditional remote sensing systems as translators of detonation commands.

The technical solution of the alleged invention is aimed at achieving a technical result, which consists in eliminating the above disadvantages, namely:

- in reducing the level of shock loads immediately at the time and after the operation of the device;

- to ensure the absence in the installation area of the charge of detonation products and high-speed metal fragments.

The specified technical result is achieved due to the fact that the shell of the charge is multilayer, consisting of one, two or more non-metallic layers (shells) with different acoustic stiffness, tightly set (without air gaps) on a detonating elongated charge in a metal (for example, in aluminum ) to the shell, provided that each subsequent layer, when the shock wave moves from the axis of the charge to the periphery, is more compressible than the previous one, with the thicknesses of these layers established on the basis of the condition for ensuring mini the smallest mass and dimensions of the charge-translator and the fulfillment of the condition for maintaining the continuity of the shell of the detonating elongated charge p _vn ≤ _{p 1cr} , where p _vn is the pressure on the outer surface of the outer shell of the translator; p _1cr is the critical pressure of the destruction of the DPS shell, arising from the assumption of a U-shaped pressure profile in the outer layer (shell), which ensures a certain margin in the desired thicknesses of the layers worn on the metal shell of the DPS. In this case, the optimal thickness of the DPS shell is 0.8 ÷ 1.2 mm, and the diameter of the explosive should be greater than the critical diameter of its detonation. To improve the mass-dimensional characteristics of the charge, its equipment can be made of small-crystalline heat-resistant explosive of reduced power with a detonation speed not exceeding 7500 m / s, with a high, more than three, polytropic exponent of detonation products and a small critical detonation diameter (not more than 1, 5 ÷ 2.0 mm). The caps worn on the ends of the charge are equipped with an explosive, composition or explosive composition of several press-fittings, the press-fit with the highest density being placed in the bottom of the caps.

The use of a multilayer shell in the design of an detonating elongated charge with a dense fit of layers (shells) one on top of another and with the correct alternation of materials of these layers allows one to obtain a charge-translator, in which the internal (aluminum) shell (DLD shell) retains its continuity when the detonation is explosive, and the outer shells can be destroyed in this case, but with the formation of low-speed belt-shaped fragments. Detonation products will be channeled by the casing of the SPS. A reasonable combination of materials of the layers of the multilayer shell and their thicknesses helps to minimize the mass-dimensional characteristics of the device. By calculating, solving the problem of motion in the first approximation of a purely radial shock wave from the center of the diametric cross section of the remote sensing system to the periphery, taking into account its transitions from one dense medium (shell) to another, it is easy to establish that acoustic stiffnesses (products ρ ₀ с ₀ , where ρ ₀ - the density of the material of the medium, with ₀ - the speed of sound in it) of the shell materials should decrease. In other words, each subsequent layer should be more compressible than the previous one. In this case, at each transition of the shock wave from one layer to another, the shock pressure at its front will drop abruptly, which is illustrated by the graphs p = p (r), where r is the distance from the center of charge in its diametric section to the periphery shown in FIG. 1. The critical pressure p _{1cr of the} destruction of the inner shell (the shell of the RCS) is determined experimentally in practice (for example, according to our data for the RCS in an aluminum shell it is 1.77 GPa, in a copper shell - 1.96 GPa).

The radial shock wave attenuation curve in the shell (layer) for the case of sliding detonation with a degree of accuracy sufficient for practice is described by a dependence of the form: p _vn / p _x = exp [-a (δ / r ₀ ) ^c ] where a and b are empirical coefficients, obtained from the results of experiments (for example, for the vast majority of metals and alloys a = 0.665; b = 0.615).

It is easy to see that the most preferable combination of layer materials is realized when the pressure changes (see Fig. 1) along the broken line A-B-C-D-E, the less acceptable option is: A-B-C-D-F; the rest are not acceptable. Of the real available structural materials, combinations of materials are possible: aluminum - fluoroplast-4 - Kevlar; aluminum - polyurethane rubber - polyvinyl chloride plasticate, etc. When using layers of metals or their alloys, translator charges will have very large masses. It is impractical to lower the diameter of explosives in a remote sensing system below the critical diameter of detonation, because this decreases the reliability of the excitation and propagation of detonation in the charge. Optimal from the point of view of a sufficient degree of shock wave attenuation, on the one hand, and an acceptable charge mass, on the other hand, is the thickness of the remote sensing casing equal to 0.8–1.2 mm.

Thus, the feature under consideration helps to prevent the formation of high-speed metal fragments of the charge shell and the breakthrough of detonation products with a high k-phase content when the inventive device is triggered.

The use of small-crystalline heat-resistant explosives with a reduced power compared to octogen or hexogen (detonation velocity not more than 7000 ÷ 7500 m / s), with a high polytropic index (n = 3.2 ÷ 3.3) and with a small critical diameter detonation (d _cr = 1.2 ÷ 2.0 mm), such as, for example, GNDS, GNS, NTFA, etc., can significantly improve, other things being equal, the mass-dimensional characteristics of charges and the device as a whole.

The test experiments performed by the authors showed that the replacement of RDX in an elongated charge with an absolutely indestructible aluminum shell with an explosion diameter of 1 mm for explosives with GNPS allows to reduce the charge mass per unit length by 1.8 times. Thus, the feature under consideration contributes to the improvement of the mass-dimensional characteristics of the claimed device.

Equipping the caps with an explosive or explosive composition in the form of several press-fittings, while the press-fit with the highest density are placed in the bottom of the caps, gives the caps, in contrast to the prototype device, in addition to the protective function (protection of the ends of the remote sensing system from rashing explosives) the function of the detonation pulse amplifier.

The considered feature helps to increase the susceptibility of the charge to detonation from a standard means of initiation without installing an additional detonator, to increase the detonation pulse transmitted by the translator to the actuator or mechanism. The considered sign increases the reliability and stability of the claimed device.

In FIG. 2 shows an example of a device explaining the essence of the proposed solution. In FIG. 1 shows a variant of a charge-translator in a conditionally indestructible three-layer shell, where:

1 - detonating elongated charge;

2 - middle (second) layer (shell);

3 - external (third) layer (shell);

4 - equipped cap;

5 - pressing in an explosive, explosive composition or composition.

An example of a specific implementation of the claimed device can serve as a charge-translator in a conditionally indestructible shell, which is a detonating elongated charge UZ-2.86-6.5 (22/2) -A-G (marking according to the Technical conditions of the F.E. Military Academy Dzerzhinsky), on which a tube of vacuum rubber (wall thickness 2 mm) is tightly planted and a polyethylene tube with a wall thickness of 0.8 mm is placed on top of it. The marking of UZ-2.86-6.5 (22/2) -A-G is deciphered as follows:

Ultrasound - an extended charge;

2.86 - the outer diameter of the ultrasound, mm;

6.5 - the diameter of the pipe-workpiece stuffed with explosives, mm;

22/2 - size (outer diameter / wall thickness) of the original billet pipe to its constriction, mm;

And - the material of the pipe billet (aluminum);

G - type of explosive (hexogen).

Characteristics of ultrasonic testing (DPS): diameter d _in equipment (explosive) - 1.02 mm; the density ρ _{in the} explosive is 1.52 g / cm ^{3, the} thickness δ _{1 of} the ultrasonic shell is 0.93 mm. The outer diameter of the charge-translator (in a three-layer shell) is 8.4 mm; its mass is approximately 56 g / m. When the charge is undermined, the inner aluminum shell of the DLD remains intact (in a slightly inflated state); non-metallic layers (shells) put on it are destroyed with the formation of belt-like fragments. A photograph of them is shown in FIG. 3.

Claims (3)

1. The charge-translator in a conditionally indestructible multilayer shell, including a detonating elongated round-shaped charge of crystalline blasting explosive in a metal shell with metal caps worn on the ends and crimped and / or glued onto the adhesive, characterized in that the charge shell is multilayer, consisting of one, and / or two, and / or more non-metallic layers of materials with different acoustic stiffness, tightly fitted without air gaps on a detonating elongated th charge, provided that each successive layer of the shell with the shock wave moves from the periphery to the axis of the charge is more compressible than the previous one, with the thicknesses of these layers to be established on the basis of the conservation of continuity of the metal sheath of the elongated detonating charge _corolla ≤r _1kr p, where p _bn is the pressure on the outer surface of the outer shell of the charge-translator; p _1cr is the critical pressure of the destruction of the shell of a detonating elongated charge, the optimal thickness of which is 0.8 ÷ 1.2 mm, and the diameter of the explosive is not less than its critical diameter of detonation. 2. The charge-translator according to claim 1, characterized in that the equipment is made of fine-crystalline heat-resistant explosive of reduced power with a detonation speed not exceeding 7500 m / s, with a high, more than three, polytropic rate of detonation products and a critical detonation diameter not more than 1.5 ÷ 2.0 mm. 3. The charge-translator according to claim 1 or 2, characterized in that the metal caps are equipped with an explosive and / or a composition and / or explosive composition of several press-fittings, the press-fit with the highest density being placed in the bottom of the caps.

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